﻿#region License
// Copyright (c) 2007 James Newton-King
//
// Permission is hereby granted, free of charge, to any person
// obtaining a copy of this software and associated documentation
// files (the "Software"), to deal in the Software without
// restriction, including without limitation the rights to use,
// copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the
// Software is furnished to do so, subject to the following
// conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
// OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
// HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
// WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
// OTHER DEALINGS IN THE SOFTWARE.
#endregion

using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO;
using Lib.JSON.Linq;
using Lib.JSON.Utilities;
using System.Globalization;

namespace Lib.JSON.Schema
{
  /// <summary>
  /// An in-memory representation of a JSON Schema.
  /// </summary>
  public class JsonSchema
  {
    /// <summary>
    /// Gets or sets the id.
    /// </summary>
    public string Id { get; set; }
    /// <summary>
    /// Gets or sets the title.
    /// </summary>
    public string Title { get; set; }
    /// <summary>
    /// Gets or sets whether the object is required.
    /// </summary>
    public bool? Required { get; set; }
    /// <summary>
    /// Gets or sets whether the object is read only.
    /// </summary>
    public bool? ReadOnly { get; set; }
    /// <summary>
    /// Gets or sets whether the object is visible to users.
    /// </summary>
    public bool? Hidden { get; set; }
    /// <summary>
    /// Gets or sets whether the object is transient.
    /// </summary>
    public bool? Transient { get; set; }
    /// <summary>
    /// Gets or sets the description of the object.
    /// </summary>
    public string Description { get; set; }
    /// <summary>
    /// Gets or sets the types of values allowed by the object.
    /// </summary>
    /// <value>The type.</value>
    public JsonSchemaType? Type { get; set; }
    /// <summary>
    /// Gets or sets the pattern.
    /// </summary>
    /// <value>The pattern.</value>
    public string Pattern { get; set; }
    /// <summary>
    /// Gets or sets the minimum length.
    /// </summary>
    /// <value>The minimum length.</value>
    public int? MinimumLength { get; set; }
    /// <summary>
    /// Gets or sets the maximum length.
    /// </summary>
    /// <value>The maximum length.</value>
    public int? MaximumLength { get; set; }
    /// <summary>
    /// Gets or sets a number that the value should be divisble by.
    /// </summary>
    /// <value>A number that the value should be divisble by.</value>
    public double? DivisibleBy { get; set; }
    /// <summary>
    /// Gets or sets the minimum.
    /// </summary>
    /// <value>The minimum.</value>
    public double? Minimum { get; set; }
    /// <summary>
    /// Gets or sets the maximum.
    /// </summary>
    /// <value>The maximum.</value>
    public double? Maximum { get; set; }
    /// <summary>
    /// Gets or sets a flag indicating whether the value can not equal the number defined by the "minimum" attribute.
    /// </summary>
    /// <value>A flag indicating whether the value can not equal the number defined by the "minimum" attribute.</value>
    public bool? ExclusiveMinimum { get; set; }
    /// <summary>
    /// Gets or sets a flag indicating whether the value can not equal the number defined by the "maximum" attribute.
    /// </summary>
    /// <value>A flag indicating whether the value can not equal the number defined by the "maximum" attribute.</value>
    public bool? ExclusiveMaximum { get; set; }
    /// <summary>
    /// Gets or sets the minimum number of items.
    /// </summary>
    /// <value>The minimum number of items.</value>
    public int? MinimumItems { get; set; }
    /// <summary>
    /// Gets or sets the maximum number of items.
    /// </summary>
    /// <value>The maximum number of items.</value>
    public int? MaximumItems { get; set; }
    /// <summary>
    /// Gets or sets the <see cref="JsonSchema"/> of items.
    /// </summary>
    /// <value>The <see cref="JsonSchema"/> of items.</value>
    public IList<JsonSchema> Items { get; set; }
    /// <summary>
    /// Gets or sets the <see cref="JsonSchema"/> of properties.
    /// </summary>
    /// <value>The <see cref="JsonSchema"/> of properties.</value>
    public IDictionary<string, JsonSchema> Properties { get; set; }
    /// <summary>
    /// Gets or sets the <see cref="JsonSchema"/> of additional properties.
    /// </summary>
    /// <value>The <see cref="JsonSchema"/> of additional properties.</value>
    public JsonSchema AdditionalProperties { get; set; }
    /// <summary>
    /// Gets or sets the pattern properties.
    /// </summary>
    /// <value>The pattern properties.</value>
    public IDictionary<string, JsonSchema> PatternProperties { get; set; }
    /// <summary>
    /// Gets or sets a value indicating whether additional properties are allowed.
    /// </summary>
    /// <value>
    /// 	<c>true</c> if additional properties are allowed; otherwise, <c>false</c>.
    /// </value>
    public bool AllowAdditionalProperties { get; set; }
    /// <summary>
    /// Gets or sets the required property if this property is present.
    /// </summary>
    /// <value>The required property if this property is present.</value>
    public string Requires { get; set; }
    /// <summary>
    /// Gets or sets the identity.
    /// </summary>
    /// <value>The identity.</value>
    public IList<string> Identity { get; set; }
    /// <summary>
    /// Gets or sets the a collection of valid enum values allowed.
    /// </summary>
    /// <value>A collection of valid enum values allowed.</value>
    public IList<JToken> Enum { get; set; }
    /// <summary>
    /// Gets or sets a collection of options.
    /// </summary>
    /// <value>A collection of options.</value>
    public IDictionary<JToken, string> Options { get; set; }
    /// <summary>
    /// Gets or sets disallowed types.
    /// </summary>
    /// <value>The disallow types.</value>
    public JsonSchemaType? Disallow { get; set; }
    /// <summary>
    /// Gets or sets the default value.
    /// </summary>
    /// <value>The default value.</value>
    public JToken Default { get; set; }
    /// <summary>
    /// Gets or sets the extend <see cref="JsonSchema"/>.
    /// </summary>
    /// <value>The extended <see cref="JsonSchema"/>.</value>
    public JsonSchema Extends { get; set; }
    /// <summary>
    /// Gets or sets the format.
    /// </summary>
    /// <value>The format.</value>
    public string Format { get; set; }

    private readonly string _internalId = Guid.NewGuid().ToString("N");

    internal string InternalId
    {
      get { return _internalId; }
    }

    /// <summary>
    /// Initializes a new instance of the <see cref="JsonSchema"/> class.
    /// </summary>
    public JsonSchema()
    {
      AllowAdditionalProperties = true;
    }

    /// <summary>
    /// Reads a <see cref="JsonSchema"/> from the specified <see cref="JsonReader"/>.
    /// </summary>
    /// <param name="reader">The <see cref="JsonReader"/> containing the JSON Schema to read.</param>
    /// <returns>The <see cref="JsonSchema"/> object representing the JSON Schema.</returns>
    public static JsonSchema Read(JsonReader reader)
    {
      return Read(reader, new JsonSchemaResolver());
    }

    /// <summary>
    /// Reads a <see cref="JsonSchema"/> from the specified <see cref="JsonReader"/>.
    /// </summary>
    /// <param name="reader">The <see cref="JsonReader"/> containing the JSON Schema to read.</param>
    /// <param name="resolver">The <see cref="JsonSchemaResolver"/> to use when resolving schema references.</param>
    /// <returns>The <see cref="JsonSchema"/> object representing the JSON Schema.</returns>
    public static JsonSchema Read(JsonReader reader, JsonSchemaResolver resolver)
    {
      ValidationUtils.ArgumentNotNull(reader, "reader");
      ValidationUtils.ArgumentNotNull(resolver, "resolver");

      JsonSchemaBuilder builder = new JsonSchemaBuilder(resolver);
      return builder.Parse(reader);
    }

    /// <summary>
    /// Load a <see cref="JsonSchema"/> from a string that contains schema JSON.
    /// </summary>
    /// <param name="json">A <see cref="String"/> that contains JSON.</param>
    /// <returns>A <see cref="JsonSchema"/> populated from the string that contains JSON.</returns>
    public static JsonSchema Parse(string json)
    {
      return Parse(json, new JsonSchemaResolver());
    }

    /// <summary>
    /// Parses the specified json.
    /// </summary>
    /// <param name="json">The json.</param>
    /// <param name="resolver">The resolver.</param>
    /// <returns>A <see cref="JsonSchema"/> populated from the string that contains JSON.</returns>
    public static JsonSchema Parse(string json, JsonSchemaResolver resolver)
    {
      ValidationUtils.ArgumentNotNull(json, "json");

      JsonReader reader = new JsonTextReader(new StringReader(json));

      return Read(reader, resolver);
    }

    /// <summary>
    /// Writes this schema to a <see cref="JsonWriter"/>.
    /// </summary>
    /// <param name="writer">A <see cref="JsonWriter"/> into which this method will write.</param>
    public void WriteTo(JsonWriter writer)
    {
      WriteTo(writer, new JsonSchemaResolver());
    }

    /// <summary>
    /// Writes this schema to a <see cref="JsonWriter"/> using the specified <see cref="JsonSchemaResolver"/>.
    /// </summary>
    /// <param name="writer">A <see cref="JsonWriter"/> into which this method will write.</param>
    /// <param name="resolver">The resolver used.</param>
    public void WriteTo(JsonWriter writer, JsonSchemaResolver resolver)
    {
      ValidationUtils.ArgumentNotNull(writer, "writer");
      ValidationUtils.ArgumentNotNull(resolver, "resolver");

      JsonSchemaWriter schemaWriter = new JsonSchemaWriter(writer, resolver);
      schemaWriter.WriteSchema(this);
    }

    /// <summary>
    /// Returns a <see cref="T:System.String"/> that represents the current <see cref="T:System.Object"/>.
    /// </summary>
    /// <returns>
    /// A <see cref="T:System.String"/> that represents the current <see cref="T:System.Object"/>.
    /// </returns>
    public override string ToString()
    {
      StringWriter writer = new StringWriter(CultureInfo.InvariantCulture);
      JsonTextWriter jsonWriter = new JsonTextWriter(writer);
      jsonWriter.Formatting = Formatting.Indented;

      WriteTo(jsonWriter);

      return writer.ToString();
    }
  }
}